– No Air. …
– High speeds only. …
– Low speed only. …
– Fan won’t turn off. …
– Blower motor works on some settings but not others. …
– Smoking vents. …
– Burning smell.
Thereof, How do you test a blower motor with a multimeter?
Using a multimeter set on the Ohm scale, use the positive lead and test the black wire. To check the purple wire for current, use your ignition key and turn it to the run setting, turn the heater power to full power and set the multimeter to DC power. If your meter reads “no current” the motor is no good.
Also to know is, What happens when blower motor resistor goes bad? The most common symptom of a failed blower motor resistor is when the heater fan only runs at the highest speed setting (4 or 5) and doesn’t work at low speeds. In some cars, a failed blower motor resistor can cause a heater fan to stop working completely.
Subsequently, question is, How do you test a blower motor resistor with a multimeter? Check the electric resistance of each of the resistor’s terminals with a multimeter. Set the tool to read ohms (a measurement of resistance) and connect one of its probes to the common output terminal of the resistor.
Also, How do I know if my AC resistor is bad?
– Blower motor stuck on one speed. …
– Blower motor does not work on certain settings. …
– No air from the vehicle’s vents.
How do I know if I have blower motor or resistor?
If you have faulty blower motor resistor you may experience low airflow coming from the vents even when the fan is all the way on high. In some cases bad blower motor resistor may not even turn the blower motor fan as a result your fan will not work at all and there will be no air coming from the vents.
How do you test a blower motor?
What does an AC resistor do?
The blower motor resistor is an electrical component that is a part of the vehicle’s heating and air conditioning system. It is responsible for controlling the blower motor’s fan speed. … A failed blower motor resistor can cause issues with the operation of the entire heating and air conditioning system.
What causes blower motor resistor failure?
In most cases, a blower motor resistor fails due to corrosion or overheating. Sometimes, the mechanical resistance to the motor rotation causes an excessive electric current that can overheat and prematurely damage the blower motor resistor.
Can you bypass a blower motor resistor?
In the highest speed state, the blower resistor is bypassed completely and the fan is connected directly to the car’s battery, which allows maximum current through the motor. … A blower motor resistor or a blower motor control module is the part that controls the speed of the blower motor.
Can you bypass blower motor resistor?
In the highest speed state, the blower resistor is bypassed completely and the fan is connected directly to the car’s battery, which allows maximum current through the motor. … A blower motor resistor or a blower motor control module is the part that controls the speed of the blower motor.
Can a resistor be shorted?
Generally speaking resistors fail short circuit, but a high value resistor, with a voltage across it exceeding its maximum voltage rating, can fail short by arcing over, which can drastically reduce the resistance value. … More often they just become higher resistance rather than becoming completely open.
How do I know if I need a blower motor or a resistor?
No air from the vehicle’s vents Another symptom of a faulty blower motor resistor is no air from the vehicle’s vents at all. … A blower motor without power will not be able to produce any air pressure, and as a result the heating and air conditioning system will be left with no air coming from the vents.
Will a blower motor work without the resistor?
The blower motor resistor is the component directly responsible for controlling the blower motor fan speed. If the resistor shorts or fails, it may cause the blower motor to remain stuck on one fan speed.
What makes a blower motor go bad?
In a situation where the motor doesn’t work on any speed, the most likely causes are: a blown power supply fuse, a bad motor ground connection, bad motor speed control module or a failed motor. On all systems, a failed blower motor is least likely. Start by checking the blower fuse and HVAC controller fuse.
Can I bypass the blower motor resistor?
In the highest speed state, the blower resistor is bypassed completely and the fan is connected directly to the car’s battery, which allows maximum current through the motor. … A blower motor resistor or a blower motor control module is the part that controls the speed of the blower motor.
What is the purpose of a blower motor resistor?
Blower resistors are resistors which are used to control the fan speed of automotive blowers. The fan speed can be changed either by switching the blower resistor resistance mechanically, using a rotating lever, or electronically by the air conditioning system.
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